Nail-driving device

ABSTRACT

A nail-driving device for securing a mounting strap assembly to a wall. The strap assembly is in the form of a curved bendable strip which is pierced substantially at its mid portion by a headed nail the head of which is located at the inside of the strip curvature. The assembly is fittable into the muzzle portion of a gun-type nail-driving device and is propelled out of the device by pressure generated in the same and released by actuation of a trigger mechanism. The strap assembly when inserted in the muzzle portion of the device is steadied in the same so that it is propelled therefrom in a direction normal to the wall into which the nail of the assembly is to be driven.

United States Patent NAIL-DRIVING DEVICE 4 Claims, 12 Drawing Figs.

US. Cl 227/10 Int. Cl 1325c 11/14 Field 01 Search 227/8, 9, 10, 1 l

[ 1 a am [56] References Cited UNITED STATES PATENTS 2,863,149 12/1958 Kopf et al. 227/11 3,040,325 6/1962 Remond 227/1 1 Primary Examiner-Granville Y. Custer, Jr. Attorney-Plane & Baxley ABSTRACT: A nail-driving device for securing a mounting strap assembly to a wall. The strap assembly is in the form of a curved bendab le strip which is pierced substantially at its mid portion by a headed nail the head of which is located at the inside of the strip curvature. The assembly is fittable into the PATENTEUJUNZSE]?! 3 5 9,5 4

sum 1 or 2 'IIIIIIIIII' FIG. 2

PRIOR ART I N VEN TORS BORJE CHI. 55 ON BY TURE OHLSSON Arrow" NAIL-DRIVING DEVICE The present invention relates to naildriving device.

There are widely known and used nail-driving devices ofthc general kind above referred to in the form of a hand gun, that is, the device has a barrel in the muzzle of which the nail to be driven is inserted with its point facing forwardly and its head fitting the diameter of the bore of the barrel. Pressure generated in the barrel, for instance by dctonating a gasgcnerating charge or by means of compressed air, is released by a trigger mechanism similar in principle to the trigger mechanism used to detonate the cartridge in the chamber ofa gun firing a projectile, and such pressure is used to propel the nail out of the barrel and into a wall or other structure.

Obviously, the shank of the nail, its diameter being generally much smaller than that of the head, is not steadied in the barrel so that there is a likelihood or at least a possibility that the nail will not be driven into the wall straight, that is, normal to the surface of the wall but at a slant, or-thc nail may even becomejammed in the muzzle. To steady the nail and to assure that it enters the wall normal to the plane thereof, it is known to fit upon the shank of the nail a washer, the diameter of which corresponds to the inner diameter of the bore of the barrel at the muzzle end thereof.

It has become common practice during recent years to secure electric wiring such as B-X cables and also pipes of small diameter to building walls and other structures by means of a curved strap defining an entry, gap for insertion of the wires and/or pipes. The strap itself is secured to the wall or other structure by a nail or screw fitted through a portion of the strip, generally a portion opposite to the gap preferably through the midpoint of the strip. The wiring and/or pipes are then inserted through the gap after spreading the same if necessary. Finally, the strip is pressed more or less tight over the components inserted therein.

It was heretofore necessary to hand-mount the strap assembly on the wall or other support structure by a tool such as a hammer or screwdriver. Such hand mounting is time consuming and hence expensive. A great number of strap assem blies must often be mounted and the walls of modern buildings are frequently made of concrete, which makes it difficult to force nails or screws into the walls and the mounting frequently requires special operations.

It is a broad object of the present invention to provide a novel and improved nail-driving device of the general type above referred to which is capable of power driving mountingstrap assemblies as hereinbefore described into a support structure. As is evident, such power driving of a nail assembly reduces the mounting time and hence the costs of installing wiring and/or piping.

A more specific object of the invention is to provide a novel and improved nail-driving device of the general kind above referred to in which the mounting-strap assembly while being in the device, and also while being ejected from the same, is safely guided so that the nail of the assembly will enter the support member in the correct, that is, straight position in reference thereto.

Another more specific object of the invention is to provide a novel and improved mounting-strap assembly for use with a nail-driving device of the kind above referred to which assembly permits the insertion into the device in fully assembled condition and is automatically guided into a position in which it is retained in the correct orientation in the device.

Still another more specific object of the invention is to pro vide a novel and improved nail-driving device and a novel and improved mounting-strap assembly therefor, the strip of which serves a dual function, namely to steady the nail of the as sembly in the device to assure straight driving of the nail and to form a mounting strap for wires and/or pipes.

In contradistinction thereto, the usefulness of the washers as were heretofore used to steady the nail in the driving device is limited to this one function.

Other and further objects, features and advantages of the invention will be pointed out hereinafter, and set forth in the appended claims constituting part of the application.

In the accompanying drawing, a preferred embodiment of the invention is shown by way ofillustration and not by way of limitation. a

In the drawing:

FIG. 1 is a perspective view, partly in section, of the forward or muzzle portion of a gun modified according to the invention;

FIG. 2 is a lengthwise sectional view of the gun according to the invention, ready for insertion of the strap assembly into the muzzle portion of the gun;

FIG. 3 is a perspective view ofa mounting-strap assembly;

FIG. 4 is a sectional view similar to FIG. 3, showing the strap assembly inserted into the gun;

FIG. 5 is a view similar to FIG. 4 in the position in which the gun is ready for securing the strap assembly to a wall;

FIG. 6 is a sectional perspective view showing the gun in the operational stage of FIG. 5;

FIG. 7 is an enlarged end view upon the muzzle of the gun either in the position of FIG. 5 or FIG. 6;

FIG. 8 is a sectional view similar to FIG. 5, but after completion of the driving operation; and

FIG. 9 shows the mounting-strap assembly secured to a wall.

Referring first to FIGS. I and 2, there is shown a nail-driving gun, the barrel of which is made of two parts I and 2, screwed to each other. Of course, the barrel may also be a one-piece barrel. A sleeve-shaped cartridge can be fired in a conventional manner by activating a firing mechanism by pulling a trigger 6. The firing mechanism should be visualized as being conventional, and does not constitute part of the invention. A suitable firing mechanism is fully described, for instance, in prior U.S. Pat. No. 3,275,209 issued to the assignee herein on Sept. 27, I966.

Barrel 1, 2 has through part of its length a bore 7 the inner diameter of which corresponds to the diameter of the head 8 of a nail 9.

-Bore portion 7 is continued by an enlarged bore portion 13 constituting part of the firing mechanism (not shown). A striker bolt I5 slidably extends into bore portion 7, preferably through a scaling 40 and is propelled forwardly upon activation of the firing mechanism.

The barrel is encased by a jacket consisting of two parts 16 and 17. Of course, the jacket may also be a one-piece jacket.

Turning now to FIG. 3, this figure shows in detail the mounting-strap assembly according to the invention. The assembly comprises a strip 19 preferably made of a bendable metal. The strip is suitably bent, preferably circularly, so that a gap is left between short edges 20 and 211 of the strip. The nail 8, 9 to be driven is forced through the strip with a tight fit with the head of the nail on the inside of the curvature of the strip. The nail is so located that it approximately bisects the gap, or in other words, it pierces the strip approximately at the midpoint thereof. A nail of any suitable material may be used; generally a hard and fairly heavy nail is advisable.

The gun which is used for driving the assembly should be visualized as being of generally conventional design except for the forward or muzzle portion thereof.

According to FIG. I the portion 2 of the barrel is formed with an axial slot 23 defining two legs 24 and 25. The sidewalls of the slot are flat as is indicated at 26 and 27 (see also FIG. 7). The outside of the legs also have fiat sides 28 and 29 joined to a cylindrical portion 18 of barrel part 2 by shoulders 28 and 29 respectively. The outer diameter of barrel portion 18 corresponds to the inner diameter of jacket part 17 but is smaller than the inner diameter of a jacket portion 30, as is clearly shown in FIGS. 5, 6 and 8.

The gun is loaded with a strap assembly as it is indicated in FIGS. 2 and 4. As shown in FIG. 4, the strap assembly is fitted in the muzzle portion so that its strip I9 rests in slot 23 abutting against the base thereof. Head 8 of the nail extends into bore 7, as is also shown in FIG. 4. The strip of the assembly isheld in position by engagement of its lengthwise edges with the sidewalls 26 and 27 of the slot and by its short edges 20 and 21 engaging the flat outer sidewalls 28 and 29.

By making the gap slightly narrower than the outer distance between sidewalls 28 and 29, the strip is in frictional engagement with said sidewalls due to the inherent resiliency of the strip material. Moreover, FIG. 7 shows clearly that the strip engages the inner diameter ofjacket portion 30 at points 32, 33, 34 and 35.

Accordingly, the strip being positively guided holds and steadies the nail in the barrel bore 7.

To ready the gun for driving a nail, the protruding muzzle portion thereof is pressed from the position of FIG. 4 into the position of FIG. by pressing the protruding muzzle portion against wall 31. The nail being held in the correct position normal to the wall is driven into the same when the firing mechanism of the gun is activated.

FIG. 9 shows the strap assembly secured to the wall and ready to receive wires and/or pipes to be mounted.

The strip may be given a configuration different from the one listed. It is only necessary that the strip in relation to the muzzle configuration is so shaped that it is capable of locating the nail prior to the activation of the gun. For instance, the strip may have a middle portion which fits the width of the slot but the parts of the strip not engageable with the sidewalls of the slot may be wider or narrower than the width of the slot.

Movement of the muzzle portion from the safety position of FIG. 4 into the driving position of HO. 5 forces the strip to move into the narrow portion ofjacket portion 17. If the strip which has a maximal width across its curvature which just fits the diameter of wide jacket portion 30, it will be slightly squeezed together when entering jacket portion 17. This has the advantage that the gun is capable of accepting strap assemblies within rather wide range of tolerances. Strap assemblies of the kind here involved are not precision elements and moreover are likely to be somewhat deformed when stored or handled. Accordingly, the possibility of using strap assemblies within a wide range of tolerance reduces the manufacturing costs thereof.

What we claim is:

l. A nail-driving device comprising in combination:

a jacket;

a bored barrel having at one end of the bore a chamber for generating a propellant pressure therein and at the other end a muzzle portion for receiving therein a mounting strap assembly including a headed nail extended with a tight fit through a curved strip with the nail head on the inside of the strip curvature, the maximum width of the nail head matching the diameter of the barrel bore for insertion therein, said barrel being lengthwise slidable within the jacket between a safety position in which the muzzle portion of the barrel protrudes from the respective jacket end and a driving position in which said muzzle portion is substantially flush with said jacket end;

a piston slidable in the barrel bore, one side of said piston being adjacent to said chamber for propelling the piston toward the muzzle portion by pressure generated in said chamber and the other side being engageable with a nail head facing the barrel to propel an assembly received in said muzzle portion out of the same by propulsion of the piston upon release of pressure generated in the chamber, said muzzle portion having in its end face an axial slot defining two legs, the width of the slot matching the width of the curved strip of the assembly at least at the midportion thereof;

whereby the strip ofa mounting-strap assembly fitted in said slot with the nail head facing the barrel bore is steadied at its lengthwise edges by the sidewalls of the slot.

2. A nail-driving device according to claim 1 wherein the outer sidewalls of said legs are flat and extend beyond the depth of the slot, the sidewalls of the slot being also flat and parallel to the flat sidewalls of the slot whereby the two lengthwise edges of the strip rest against the sidewalls of the slot and the short edges at the ends of the strip abut against the flat sidewalls of the legs thus steadying the strip at the four edges thereof.

3. A nail'driving device according to claim 1 wherein the axial depth of the slot is such that the nail head protrudes into the barrel bore when the midportion of the strip rests upon the base of said slot.

4. A nail-driving device according to claim 1 wherein the jacket has at is end adjacent to the muzzle portion a contiguous outer portion and inner portion, the inner diameter of the outerjacket portion and the curvature of the strip being so correlated that the diameter of said outer portion fits the maximum width of the strip curvature and that the diameter of the inner jacket portion is less than said maximum width of the strip curvature. 

1. A nail-driving device comprising in combination: a jacket; a bored barrel having at one end of the bore a chamber for generating a propellant pressure therein and at the other end a muzzle portion for receiving therein a mounting strap assembly including a headed nail extended with a tight fit through a curved strip with the nail head on the inside of the strip curvature, the maximum width of the nail head matching the diameter of the barrel bore for insertion therein, said barrel being lengthwise slidable within the jacket between a safety position in which the muzzle portion of the barrel protrudes from the respective jacket end and a driving position in which said muzzle portion is substantially flush with said jacket end; a piston slidable in the barrel bore, one side of said piston being adjacent to said chamber for propelling the piston toward the muzzle portion by pressure generated in said chamber and the other side being engageable with a nail head facing the barrel to propel an assembly received in said muzzle portion out of the same by propulsion of the piston upon release of pressure generated in the chamber, said muzzle portion having in its end face an axial slot defining two legs, the width of the slot matching the width of the curved strip of the assembly at least at the midportion thereof; whereby the strip of a mounting-strap assembly fitted in said slot with the nail head facing the barrel bore is steadied at its lengthwise edges by the sidewalls of the slot.
 2. A nail-driving device according to claim 1 wherein the outer sidewalls of said legs are flat and extend beyond the depth of the slot, the sidewalls of the slot being also flat and parallel to the flat sidewalls of the slot whereby the two lengthwise edges of the strip rest against the sidewalls of the slot and the short edges at the ends of the strip abut against the flat sidewalls of the legs thus steadying the strip at the four edges thereof.
 3. A nail-driving device according to claim 1 wherein the axial depth of the slot is such that the nail head protrudes into the barrel bore when the midportion of the strip rests upon the base of said slot.
 4. A nail-driving device according to claim 1 wherein the jacket has at is end adjacent to the muzzle portion a contiguous outer portion and inner portion, the inner diameter of the outer jacket portion and the curvature of the strip being so correlated that the diameter of said outer portion fits the maximum width of the strip curvature and that the diameter of the inner jacket portion is less than said maximum width of the strip curvature. 